The contractor shall conduct a comprehensive and systematic evalution of the strategies that communities across the country have initiated to prevent childhood obesity. Documentation concerning the range and extent of efforts in which communities are investing to prevent childhood obesity is limited, and large-scale evaluation of community-based programs and policies aimed at combating childhood obesity does not yet exist. Comprehensive multicomponent programs have the potential to make the greatest impacts, but have not been systematically examined, and no studies have conducted analyses to determine the relative contribution of the various intervention components to the measured outcomes. Further, very few studies have examined the extent of implementation of various program models and components, contextual factors that influence long-term impacts, program sustainability, feasibility, or potential for wide-spread program dissemination. The study of relative impacts of different interventions across varying studies has been limited by methodological differences and by differences in the study populations and locations. Very little is known about the minimum intervention intensity or combination of approaches needed for measurable impact. In addition, little is known about the community factors and processes that are important to enable effective implementation and sustenance of promising intervention approaches. This study will help fulfill the need for this critical information, enabling people to work together in communities to create conditions for healthy nutrition and physical activity for all our children.